Technical Field
The present disclosure relates to a power supply system including a battery energy storage system.
Description of the Related Art
Electric energy is in wide use because of its easy transformation and transmission. An energy storage system is used to use the electric energy with high efficiency. The energy storage system is charged with electric power. In addition, as necessary, the energy storage system is discharged to supply the stored power. This facilitates flexible supply of power.
Specifically, when a power generation system includes a battery energy storage system, an operation is performed as follows. If a load or a grid is a heavy load, the energy storage system discharges electric energy. If a load or a grid is a light load, the energy storage system is charged with power supplied from a power generator or a grid.
If the energy storage system exists independent of the power generation system, the energy storage system is charged with idle power supplied from an external power source. If a grid or a load is a heavy load, the energy storage system supplies power by discharging the stored power.
A power supply system may include a plurality of power conversion systems for duplexing and maximization of power conversion efficiency. In this case, a system controller has to control the plurality of power conversion systems with high efficiency. In particular, the system controller has to be able to transmit a control instruction to the plurality of power conversion systems with high efficiency.